Your 'beemie' and everyone else's E30 don't have to take a back seat or worry about these anomalies

Just the same, I wouldn't mind having a simpler 200hp version with a greater range on a charge
Actually, a 150hp version would still provide more grunt than the stock 2.5 gasoline engine...electric motors develop a lot of torque to go along with the hp!

Your 'beemie' and everyone else's E30 don't have to take a back seat or worry about these anomalies

Just the same, I wouldn't mind having a simpler 200hp version with a greater range on a charge
Actually, a 150hp version would still provide more grunt than the stock 2.5 gasoline engine...electric motors develop a lot of torque to go along with the hp!

More importantly, they don't have a torque curve! Electric motors produce the same torque from 0 to max RPM. This results in the HP output not ring a curve, but a linear line going up and up and up

QuoteEarendilElectric motors produce the same torque from 0 to max RPM. This results in the HP output not ring a curve, but a linear line going up and up and up

I don't believe that's true.

Electric motors produce the greatest torque at startup, i.e. at zero rpm. The torque falls off as the rpm increases.

You know, I lost my modifying word at some point in the corrections. I really need to stop making posts here on my iPhone...

I believe the torque curve is "effectively" flat. Correct me if I'm wrong, but gas powered cylinder based engines have a half dozen inputs and a dozen or more variables that produce different engine efficiencies at different RPMs. Electric motors have no such variables, and are mostly effected by friction. Now there are other electrical variables that will modify the torque (thus an electric drill can have multiple "speeds" with the same power supply), but these tend to not be inherent inefficiencies the way you see them on gas powered engines. There are of course RPM limits based on mechanics and the supply of current (half dead battery = less torque).

THAT said, what I know comes from an electronics class that was not about motors. These few tidbits are what I gleaned from comments made by the professor. I would not doubt that there are multiple ways to create an electric motor, and that the torque curves for each type would be vastly different depending on the application they were designed for. Ferd, do you know whether or not the electric motors used in vehicle applications tend towards having a torque curve that substantially drops off due to something besides friction?

My ever so slightly better than uneducated guess, is that before the torque drop is what would be considered the operating range. Tesla, according to Top Gear, only has a single gear for that car because they kept breaking the gear box. So with a single gear they have to spin the engine up to 14,000 just to get to 120mph.
If they had 4 gears and a double clutch transmission, they could rev limit it to 6k and have an effectively smooth torque curve up to well past 120mph. Of course, they would have to remove some of the batteries that they crammed into every inch of that car ;-)

Ferdinand and Earendil, You are both right, and both incomplete.
There are deferent types of motors.
the DC series motor has maximum Torque at zero rpm, decreasing when rpm increase to give a somewhat flat Power output, it is widely used in vehicles like trains, trams, cars, etc...
The DC parallel motor has less starting Torque, increasing Power.
The AC 3 phase motor has fixed rotation speed, depending on the frequency of the voltage applied, which can be controlled with modern electronic motor drives. These have the advantage of the simplest construction and ruggedness.
There are also brush-less DC motors, servo motors, stepper-motors, etc. Each has it's own Torque and Power curves, and the corresponding way to control speed and power. Some are better than other to work both as motor or generator, important for dynamic braking and energy recovery.

The weak point, now like 100 years ago, is the batteries needed to make an electric car usable. Those are very expensive, bulky, heavy and can last only a given number of charge-discharge cycles. Also the raw materials needed to build the battery pack includes hazardous chemicals, and some are not easy to recycle or dispose.
I wouldn't consider a battery electric car "environmentally clean", it produces no exhaust but it has polluted to be built, the energy has to be produced somewhere to charge it, and it will be (when old) a dangerous residue.

My ever so slightly better than uneducated guess, is that before the torque drop is what would be considered the operating range. Tesla, according to Top Gear, only has a single gear for that car because they kept breaking the gear box. So with a single gear they have to spin the engine up to 14,000 just to get to 120mph.
If they had 4 gears and a double clutch transmission, they could rev limit it to 6k and have an effectively smooth torque curve up to well past 120mph. Of course, they would have to remove some of the batteries that they crammed into every inch of that car ;-)

EV cars need no gears or clutches cause the motor can develop power from zero rpm, unlike internal combustion engines.
The horizontal part of the graph is maximum Torque, the decreasing torque is limited by the maximum voltage and current the motor wire-windings can take.
There is no problem in using the motor at that regime, over brief periods.

My ever so slightly better than uneducated guess, is that before the torque drop is what would be considered the operating range. Tesla, according to Top Gear, only has a single gear for that car because they kept breaking the gear box. So with a single gear they have to spin the engine up to 14,000 just to get to 120mph.
If they had 4 gears and a double clutch transmission, they could rev limit it to 6k and have an effectively smooth torque curve up to well past 120mph. Of course, they would have to remove some of the batteries that they crammed into every inch of that car ;-)

EV cars need no gears or clutches cause the motor can develop power from zero rpm, unlike internal combustion engines.
The horizontal part of the graph is maximum Torque, the decreasing torque is limited by the maximum voltage and current the motor wire-windings can take.
There is no problem in using the motor at that regime, over brief periods.

I understand that there is no need for a clutch, but wouldn't a few gears allow the electric motor to operate within a more suitable range? I would assume that it would be able to generate a higher torque at a lower RPM... but perhaps the decrease in torque has more to do with load caused by wind resistance than it does the RPM?

I understand that there is no need for a clutch, but wouldn't a few gears allow the electric motor to operate within a more suitable range? I would assume that it would be able to generate a higher torque at a lower RPM... but perhaps the decrease in torque has more to do with load caused by wind resistance than it does the RPM?

If there were gears, one would need a clutch or something to change them.
If you look at EV practice over the last 120years, there is not much to be gained in using gears, just a final drive.
Large electric locomotives have gears, one low used to heavy freight train at lower speed, other for higher speed express train.
The best in using electric motors is exactly that, useful power all the way from zero rpm to maximum (usually about 6000 for DC motors)
And no, the decrease in Torque above certain Power (maximum nominal ) has to do with maximum Voltage and current limits the motor can take.
The wind friction and all that doesn't affect much the motor.

I understand that there is no need for a clutch, but wouldn't a few gears allow the electric motor to operate within a more suitable range? I would assume that it would be able to generate a higher torque at a lower RPM... but perhaps the decrease in torque has more to do with load caused by wind resistance than it does the RPM?

If there were gears, one would need a clutch or something to change them.
If you look at EV practice over the last 120years, there is not much to be gained in using gears, just a final drive.
Large electric locomotives have gears, one low used to heavy freight train at lower speed, other for higher speed express train.
The best in using electric motors is exactly that, useful power all the way from zero rpm to maximum (usually about 6000 for DC motors)
And no, the decrease in Torque above certain Power (maximum nominal ) has to do with maximum Voltage and current limits the motor can take.
The wind friction and all that doesn't affect much the motor.

I was amazed when I drove my friends prius; it had much more power than I thought it would before the gas motor kicked in. Ever since I've looked at electric cars with a whole new view. I wonder what the Volt feels like

Well, what I have read/heard is that if you amortize the battery cost, you would be surprised at what the real cost of the car is per mile. And surprisingly, manufacturing a Prius compared to a conventional car is not as green a process as manufacturing a conventional car. I believe hybrids are viewed as a transient technology, not the answer. As for the Volt, what I don't understand is how people think they are driving for free. The last time I checked, Edison always sends me a bill for electricity used (the cars don't charge themselves). Add in the $40,000+ pricetag, well, you get my drift here.

Quotealanrw
Well, what I have read/heard is that if you amortize the battery cost, you would be surprised at what the real cost of the car is per mile. And surprisingly, manufacturing a Prius compared to a conventional car is not as green a process as manufacturing a conventional car. I believe hybrids are viewed as a transient technology, not the answer. As for the Volt, what I don't understand is how people think they are driving for free. The last time I checked, Edison always sends me a bill for electricity used (the cars don't charge themselves). Add in the $40,000+ pricetag, well, you get my drift here.

alan

Yeah. Buying a new electric car do not save you money, even in the long run. The only reason to buy an electric car is to help the environment. Yes, they possibly cause more problems during production then does a "regular" vehicle, but if you consider the life of a vehicle, it's quite possible we'll have a better means of disposing of the parts in the future. However the fumes put out by a tradition vehicle over the next 20 years will not be as easy to "clean up".

I understand that there is no need for a clutch, but wouldn't a few gears allow the electric motor to operate within a more suitable range? I would assume that it would be able to generate a higher torque at a lower RPM... but perhaps the decrease in torque has more to do with load caused by wind resistance than it does the RPM?

If there were gears, one would need a clutch or something to change them.
If you look at EV practice over the last 120years, there is not much to be gained in using gears, just a final drive.

When I said there was no need for a clutch, what I mean was the use of a clutch for starting a vehicle from a stop. This is needed in an engine that achives zero torque at 0 RPM, but not in an electric car.

However, you don't need a clutch in a vehicle to archive different input-output ratios. See Continuous Variable Transmission.
I have no doubt that the Tesla car would shred modern CVTs. However it would seem that if there were such a CVT, it could serve to extend the speed at which the vehicle is traveling before the torque drops off. You wouldn't need to engage the CVT until the point at which the torque started to drop off. This would also serve to give the vehicle a better top speed, and could act as an overdrive.

Still, I can't imagine a CVT system capable of withstanding the 2000 ft-lb of torque the Tesla puts out.

That is the weak spot of the current CVT technology or it would be in highway long haul trucks right now. It's getting better but until the car or transmission companies really get serious, the CVT will lag behind.

As for all the negatives about producing and fueling electric cars...folks, we are running out of oil and will have to switch eventually. The sooner we do it, the sooner we will figure out cleaner ways of building these things and the oil that is left can still be used to produce the million other products we depend on!

Stop thinking like or listening to Big Oil or Detroit; they only fill your heads with crap that supports their earth killing agenda >:<(

QuoteArcheo-peteriX
That is the weak spot of the current CVT technology or it would be in highway long haul trucks right now. It's getting better but until the car or transmission companies really get serious, the CVT will lag behind.

As for all the negatives about producing and fueling electric cars...folks, we are running out of oil and will have to switch eventually. The sooner we do it, the sooner we will figure out cleaner ways of building these things and the oil that is left can still be used to produce the million other products we depend on!

Stop thinking like or listening to Big Oil or Detroit; they only fill your heads with crap that supports their earth killing agenda >:<(

Yes, but sad to think I'll be explaining to my grandkids someday about how cars used to go "vroom vroom". They'll soon all be going "......"

QuoteArcheo-peteriX
That is the weak spot of the current CVT technology or it would be in highway long haul trucks right now. It's getting better but until the car or transmission companies really get serious, the CVT will lag behind.

As for all the negatives about producing and fueling electric cars...folks, we are running out of oil and will have to switch eventually. The sooner we do it, the sooner we will figure out cleaner ways of building these things and the oil that is left can still be used to produce the million other products we depend on!

Stop thinking like or listening to Big Oil or Detroit; they only fill your heads with crap that supports their earth killing agenda >:<(

Yes, but sad to think I'll be explaining to my grandkids someday about how cars used to go "vroom vroom". They'll soon all be going "......"

Interesting you should say that...

Early Mazda Rotary car ads used to compare the traditional engines with 'boing, boing' or something like that with '......' or 'hmmmm'

Did anyone see the documentary called "who killed the electric car" it was very interesting how GM and the California Govt along with the big oil put a swift demise to it.
The expose center's around GM's EV1, of which hundreds were built to satisfy a law passed by the California Air Commission, or some board with that sort of name, that regulated that 10% of all cars would be emission free, with the percentages rising annually.
And how GM got them to repeal the law and then promptly reclaimed every single EV1 on the road from there owners and crushed them.
Not A single EV1 survives today, and they were very popular with their owners.
It can be found on You Tube in 5 or 6 segments, really worth a look, if you haven't seen it.
An interesting statistic about the range issue, was that the EV1 had a range of 300 miles and the average American does 29 miles a day, on their daily commute.
I used to poo poo electric cars, but look at them in a whole new light.

QuoteArcheo-peteriX
Early Mazda Rotary car ads used to compare the traditional engines with 'boing, boing' or something like that with '......' or 'hmmmm'

Here's a trip down memory lane:

I remember those ads well. My best buddy's older brother had a first generation RX-7 that I coveted. Now I own two Mazdas, but both with piston engines. Rotaries are cool, but the atrocious fuel mileage means I'll probably never own one.

Regarding electric cars, they're also cool. Obviously they're still in their infancy and nowhere near the planet-saving wonders that some people make them out to be, but cool nevertheless. I have no doubt that some day gasoline-burning engines will be a thing of the past, but whether they are replaced by electric engines, biofuel engines, batteries, hydrogen fuel cells, or anything else, or some combination of those, is still anyone's guess. Only hindsight after it's already happened will tell us for sure.

This discussion is biased perhaps, we area group of people who love to drive cars!
EV are no long-term solution, simply because electricity is not a primary energy. It is stupid to produce electricity out of natural gas or oil and use it on EV by means of large pouting battery packs, it will always be more efficient end cheap to burn the oil or gas directly on your car!
Nevertheless, energy will be more expensive, and we will have to travel less day to day, daily commuting alone in the car will be something from the past.

There are loads of ECO-bullshit and green-washing floating around.
The world will never have cheap plentiful energy our parents had back in the '60s and '70s.
Then, our "way of life" was transformed from public transport (trains, trams, bus...) to roads, high ways and private cars.
Cities exploded like oil spilled on water, the suburbs filled with houses with huge garages whose owners worked 50km away. Street shops closed and huge malls replaced them, again in the suburbs, too far out of walking range. Old cities are somewhat decayed, or turned into museums, and surrounded by the new urban/suburban areas built to accommodate automobile.
Perhaps we will have to revert back to 1920, move to live near work, use mass transit, and spend another huge pile of money to restore the transport networks that were demolished 20 or 30 years ago for being old and inefficient, this while still paying for the empty highways recently built and financed to be payed over 50 years, with estimated traffic increasing over the years.

There was some old movie on TV the other day, the action was in some small town in Texas in mid '80 and every school boy had a huge car or truck to drive anywhere. Over here in Europe small towns it's not very different, only people only drives after 18. That is what Earendill will tel his grandkids, that everyone drove a 3 ton own vehicle thousands of Km every month, without even thinking about it.
They will look at car museums and fuel prices and think: "The old guy is crazy, now he lost it completely!"

QuoteJose Pinto
It is stupid to produce electricity out of natural gas or oil and use it on EV by means of large pouting battery packs, it will always be more efficient end cheap to burn the oil or gas directly on your car!

Are you certain about that? I could be mistaken, but I seem to recall reading something that suggested the opposite. Certainly energy is lost during the transmission from power plant to the user, but energy is also lost in internal combustion engines. In fact, IIRC most of the energy in our current fuels is not ever transmitted to the wheels.